Plan and implement data platform resources →mediumMultiple Choice

DP-300 Plan and implement data platform resources Practice Question

Exhibit

Refer to the exhibit.

```sql
CREATE DATABASE SCOPED CREDENTIAL [https://mystorageaccount.blob.core.windows.net/data]
WITH IDENTITY = 'SHARED ACCESS SIGNATURE',
SECRET = 'sv=2022-11-02&ss=b&srt=sco&sp=rw&se=2025-01-01T00:00:00Z&st=2024-01-01T00:00:00Z&spr=https&sig=...';

CREATE EXTERNAL DATA SOURCE [MyDataSource]
WITH (
    LOCATION = 'https://mystorageaccount.blob.core.windows.net/data',
    CREDENTIAL = [https://mystorageaccount.blob.core.windows.net/data]
);

CREATE EXTERNAL TABLE [dbo].[ExternalTable]
(
    [ProductID] INT,
    [ProductName] NVARCHAR(100)
)
WITH (
    LOCATION = 'products/',
    DATA_SOURCE = [MyDataSource],
    FILE_FORMAT = [ParquetFormat]
);
```

You are analyzing the SQL script in the exhibit. This script is used to query data stored in Azure Blob Storage from Azure SQL Database. What is the primary purpose of the database scoped credential?

⚠ Common exam trap

It's easy for candidates to confuse the credential's role with the external data source's LOCATION or the external table's schema, but the credential is strictly an authentication mechanism, not a metadata or location definition.

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

✓

To store the shared access signature token for accessing the blob storage.

The database scoped credential in this context securely stores the Shared Access Signature (SAS) token required to authenticate and authorize access to Azure Blob Storage. When creating an external data source with the CREDENTIAL option, SQL Database uses this credential to pass the SAS token to the storage endpoint, enabling read operations for PolyBase or external table queries.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

✓
To store the shared access signature token for accessing the blob storage.
Why this is correct
The database scoped credential holds the shared access signature token that authenticates SQL Database against the blob endpoint. Without it, the external data source cannot authorise reads, so it satisfies the requirement for querying blob-stored data securely.
✗
To define the file format of the external data.
Why it's wrong here
A database scoped credential stores the identity and secret used to authenticate to the external source, not the file format. It is tempting because external file format objects and credentials appear together in the same CREATE EXTERNAL DATA SOURCE and CREATE EXTERNAL TABLE script, so the roles are easily confused.
✗
To specify the schema of the external table.
Why it's wrong here
The external table schema is declared in the CREATE EXTERNAL TABLE statement's column definitions, not in the credential. It is tempting because the credential is referenced within the same script that defines the external table, so it appears to govern the table's structure rather than its authentication.
✗
To provide the location of the external data source.
Why it's wrong here
The external data source's LOCATION clause supplies the Blob Storage endpoint; the credential only supplies authentication to it. It is tempting because both objects are created in the same script and the credential is named in the WITH clause of the data source definition, suggesting it holds the path.

Quick reference

Azure Blob Storage Tier Comparison

Tier	Storage Cost	Retrieval Cost	Latency	Use Case
Hot	Highest	Lowest	Immediate	Active data, frequent reads
Cool	Lower	Higher	Immediate	Data accessed < once / month
Cold	Lower still	Higher	Immediate	Data accessed < once / quarter
Archive	Lowest	Highest + rehydration delay	Hours	Long-term compliance retention

Go deeper

DP-300 Plan and implement data platform resources Practice Question

Exhibit

Why each option matters

Option-by-option breakdown

Azure Blob Storage Tier Comparison

Related to this question